Burner control



Aug. 16, 1960 K. s. JENsoN 2,949,236v

BURNER CONTROL FiledJuly s, 1958 2 Sheets-Sheet 1 58 VALVE FZLV/f/V.

our J3 Aug- '16, 1960 K. s. JENsoN 2,949,236

BURNER CONTROL Filed July 3, 1958 j/u K @iVm/50 2 Sheets-Sheet 2 United States Patent BURNER CONTROL Kenneth S. Jenson, Wisconsin Rapids, Wis., assignor to Preway, Inc., a corporation of Wisconsin Filed July 3, 1958, Ser. No. 746,487

4 Claims. (Cl. 236-48) This invention relates to burner control apparatus and more particularly to a thermostatic control for a burner fuel valve.

It is a general object of the invention to provide a new and improved control of the type described.

A more specific object is to provide a new and improved control of the type described including a compound lever mechanism comprised of a plurality of levers swingable together as a unit in a valve closing direction to partially close a valve, and thereafter movable relative to each other to provide a snap action for closing the valve to extinguish a burner re and having selectively operable means for locking the levers together to prevent the snap action Valve closing movement and thereby maintain a low re.

Other objects and advantages will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. l is a vertical sectional View through a burner control apparatus embodying the principles of the present invention, including control valve mechanism and a thermostatic control for the valve;

Fig. 2 is a fragmentary sectional view similar to that of Fig. l illustrating the thermostatic control in a second position;

Fig` 3 is a similar sectional view illustrating the thermostatic control in a third position;

Fig. 4 is a fragmentary top plan view illustrating the thermostatic control;

Fig. 5 is a bottom plan view of the thermostatic control; and

Fig. 6 is a transverse sectional view through the thermostatic control, taken at about the line 6 6 of Fig. l.

While an illustrative embodiment of the invention is shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in many different forms, and it should be understood that the present disclosure is to be considered as an exempliiication of the principles of the invention and is not intended to limit the invention -to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

'This invention constitutes an improvement over the burner control apparatus of the copending application 'of the present inventor and Frederick W. Suhr, led

February 19, 1958 as Serial No. 716,152, assigned to the assignee of this application.

Referring now to the drawings in more detail, the present invention is illustrated in a burner control apparatus intended for use in a system of the type shown in said copending application and including a control valve mechanism generally designated by the reference number 10 for controlling the ow of fuel oil by gravity from a suitable storage tank (not shown) to a pot type burner (not shown) and, mounted on the valve mechanism, a thermostatic control generally designated l1 for controlling the valve mechanism to thereby control burner operation.

' The valve mechanism 10 may be of a conventional manufacture similar to that illustrated in the Biermann et al. Patent 2,547,995 to which fuel oil is supplied through a conduit l2 from said storage tank. and from which fuel oil flows to said burner through a conduit diagrammatically illustrated at llv. The valve mechanism includes a casing or housing 20 Which provides a chamber or reservoir 2l into which oil flows from the conduit l2 through a strainer Z2 and an inlet valve 23. Opening and closing of the valve 23 is controlled by a valve stem Z4 which in turn is controlled by a float 25 in the chamber 2l which is supported by a lever 26 pivoted at 27 and having a suitable connection with the valve stem 24 to close the valve 23 when liuid in the chamber 21 rises to a normal oil level. The valve stem 24 is normally biased in an upward valve opening direction by a spring 2g so that when the oil in the chamber 21 falls below the normal level and the float also falls, the Valve 23 is opened under the urge of spring 29 to admit additional oil to the chamber 2l.

On rare occasions when the valve stern Z4 fails to completely close the valve 23 because of grit or other extraneous material in the valve bore, the oil continues to rise and overiiows into a safety chamber 31 provided by a wall 3M. An auxiliary or safety iloat 32 is provided in the chamber 3l and connected to a safety leverage 33 which functions to hammer the valve stem 24 to a closed position when fluid overflows the wall 31a and rises in the chamber 32. Once actuated, the safety mechanism 33 may be reset by means of a reset mechanism including an exteriorly accessible reset lever 35.

Fuel flow from the interior of the chamber 21 to the conduit 13 leading to the burner is controlled by a metering valve generally designated 3'7 and including a valve stem 38 which is biased toward a valve open position by a spring 39. Valve stem 37 is moved toward a valve closed position by a leverage generally designated 40 which in turn is actuated by a vertically reciprocable pin il slidable in a boss Ai2 on the upper portion of the housing 2li. The pin 41 is arranged to be controlled by the thermostatic control l1, as will be described presently.

ln the control valve mechanism ld, a screw 45 is adjustable to provide a compensation for variations in the grades of various fuel oils which may be used and' to 1 provide a compensation for the varying viscosities encountered With different grades of oil. An adjustable screw 416 is engageable by the leverage 4i) on upward movement of the latter and provides an adjustment for determining the maximum opening movement of the valve stem 3S and thus determines the maximum fuel tlow rate when the valve is fully open for high tiring. An adjustable screw i7 carried by the leverage 40 determines the maximum closing of the valve .37, and may be set to provide a low tire or pilot fire fuel ow rate when there is no call for heat at the thermostatic control lll. It should be understood however that, as described in said copending application, in the preferred mode of operation it is not contemplated that the adjustment screw 47 would be utilized to provide a low tire or pilot firing rate, but rather it is preferred that the valve 37 be completely closed when there is no call for heat as the apparatus is intended for an on-of type of operation.

The details of the valve control mechanism it) form no part of the present invention, and the summarizedto control operation of the valve 37 which is biasedn toward an open position.

The thermostatic control unit 11 comprises an in-' verted dish-shape support or housing 50 mountable on the top of the valve housing 26 and adapted to be secured thereon as by screws l. The support 50 has fixed thereon a hollow upright externally threaded boss 52 which provides a support for a thermostatic bulb and bellows unit responsive to ambient temperature conditions. The bulb and bellows unit includes an upright bulb 53 having a lower portion 54 threadably mounted on the boss 52 and formed with an enlarged manually accessible base or knob 55 for rotating the bulb to adjust the same. A spring 56 seated on the housing 50 biases the bulb 53 and knob 55 upwardly to maintain a tight engagement of the threads. Inside the bulb, there is provided a closed bellows 57 having a rod 58 attached to its upper end, slidable in the hollow boss S2 and terminating in a pointed bearing end 59. A spring 6i) surroundin.f7 the rod 58 urges the top of the bellows upwardly. Between the bellows and the bulb, chamber 53u is charged with a temperature responsive tluid so that on temperature rises the fluid expands, compressing the bellows and forcing the rod 58 downward. On temperature decrease, the iluid contracts allowing the bellows to expand and allowing the rod S8 to rise.

The bulb and bellows unit are arranged to control a compound leverage for operating the valve actuating pin 41. The compound leverage is pivoted on a fulcrum provided by a transverse pin 63 suitably mounted in the housing 50 as by ears 6L?, depending from the upper wall of the housing. ri`he leverage includes a iirst or actuating lever 65 pivoted on the pin 63, a second or control lever 66 pivoted on the pin 63, and a third or operating lever 67 pivoted on the control lever 66. The control lever 66 comprises an inverted channel shaped part having depending side legs 66a which terminate somewhat short of the end of the lever as at 66b. At the terminal edges `of the depending leg portions, these are provided with indentations forming a seat for the left-hand end of lever 67. An overcenter or toggle acting spring 69 has opposite ends connected respectively to the actuating lever 65 and the operating lever 67 and biasing the latter upwardly against the underside of the control lever 66 near its free end, so that the three levers are constrained to move in unison Within predetermined limits which vwill be described.

Near the fulcrum 63, the actuating lever 65 is formed with a socket 65a in which the pointed end of rod 58 `is seated. The free end of operating lever 67 has its under surface positioned to engage the valve actuating pin @il to press the latter downwardly toward valve closed position. The free end of control lever 66 carries an adjustable stop screw 71 engageable with the top of valve housing 2t) to limit movement of this lever.

In operation, the parts as positioned in Fig. l illustrate a condition existing at a time when the valve 37 is substantially fully open and the burner is operating at high tire. As the burner satisfies the demand for heat, the temperature in chamber Se rises, compressing the bellows and forcing the rod 5S downward. This pivots actuating lever 6:'3 downwardly and the three levers move in unison toward a valve closed position. On engagement of stop screw 71 with the top of housing 20, as illustrated in Fig. 2, movement of the control lever 66 is terminated, but the lever 65 is free to continue moving. Such continued movement of lever 65 eventually moves the left end of spring 69 to a position which will snap the operating lever 67 downwardly away from control lever 66 to the position illustrated in Fig. 2 wherein the valve closing movement of pin 41 has been completed, The snap action of operating lever 67 is provided to move the valve closing pin 41 quickly through the low tire so called sooty stage of operation and thereby avoid or minimize the latter.

Subsequently, when there is a need for heat, the uid in chamber 54 contracts allowing the bellows to expand and elevate the rod 5S. This enables the valve opening 4 spring 39 to force the pin 41 upwardly, thereby effecting a return of the leverage to position of Fig. l.

As indicated above, and las described in more detail in said copending application, according to the preferred mode of operation the thermostatic control is set to move the valve actuating pin 41 between opposite limits representing a high lire valve open position illustrated in Fig. l and a valve closed no lire position illustrated in Fig. 2. rIbis means that after the valve is closed, the fire in the burner eventually dies completely out so that on subsequent call for heat, the fuel must be reignited. For this purpose, a complete burner apparatus includes an electric igniter (not shown) connected in a suitable circuit including an igniter switch mounted on the valve housing 20 in a box 81 and having a switch actuating lever seen in section at 82 positioned between the valve actuating pin 41 and the operating lever 67. The switch lever 82 is positioned for actuation by the combined leverage so that the switch is closed and the igniter is energized when the valve is opened. Conversely, when the valve is closed, the switch is opened and the igniter deenergized.

In systems of the type described yintended for on-ot operation it sometimes occurs that the igniter burns out and is incapable of functioning or there occasionally occurs a power failure which prevents operation of the igniter. Obviously, under these circumstances the owner is inconvenienced due to the fact that the apparatus is set to completely close the valve and extinguish the tire when the particular demand for heat is satised so that on subsequent calls for heat, even though the valve be opened, there will be no ignition and no tire.

According to the invention, in order to overcome the disadvantages referred to in the preceding paragraph, a latch or lock is provided for selectively holding the control lever 66 and actuating lever 65 against movement relative to each other to thereby prevent the overcenter snap action valve closing movement of operating lever 67. As seen best in Figs. l, Z and 3, the improved control comprises an adjustment screw 85 threadably mounted in actuating lever 65, projecting upwardly through an opening in control lever 66, and having a knurled manually accessible upper end for adjusting the screw. During the normal mode of operation described hereinabove, the screw 85 is adjusted upwardly tothe position illustrated in Figs. 1 and 2 as determined by a retaining ring 36 on the screw engageable with lever 65. When the screw is so positioned, movement of actuating lever 65 relative to control lever 66 is permitted and theover center snap action of operating lever 67 is permitted. On the occasion of a burned out igniter or power failure, the screw 35 may be adjusted downwardly in lever 65 to the position shown in Fig. 3 wherein a shoulder 87 on the screw engages lever 66, drawing the levers 66 and 65 together. This adjustment prevents relative movement of levers 65 and 66 and prevents the over center snap action of lever 67. Accordingly, the combined leverage may be moved integrally to the position of Fig. 3 as determined by stop screw 71 wherein the valve is only partially closed, providing a flow sutiicient to sustain low iire or pilot tire operation. The screw 85 thus e11- ables `an easy conversion from on-oE operation to high tire-low fire operation without disturbing the remaining adjustments of the apparatus.

l claim:

l. For a burner fuel valve having a housing, a reciprocable valve actuating pin, and means biasing the pin outwardly of the housing in a valve opening direction, a control, comprising, a support mountable on the housing adjacent the pin, a fulcrum on the support, an actuating lever pivoted on the fulcrum, a temperature responsive motor on the support for pivoting the actuating lever in a valve closing direction, a control lever pivoted on said fulcrum and overlying the actuating lever, an

operating lever pivoted on able with said pin, a toggle spring connected between said actuating lever and said operating lever biasing the operating lever against the control lever so that the three levers are movable in unison `in a valve closing direction under urge of said motor, a stop on the control lever engageable with the housing to limit movement of the control lever in a valve closing direction beyond a pilot fire position, said motor being operable to pivot the actuating lever away from the control lever in a valve closing direction after engagement of said stop with said housing to snap said operating lever and spring overcenter away from the control lever to a valve closed position, and a selectively operable latch for locking the actuating lever to the control lever to prevent relative movement therebetween land thereby prevent the snap action valve closing movement of the operating lever comprising a screw threaded in the actuating lever projecting upwardly through an opening in the control lever and having a manually accessible portion thereon for adjustment thereof, and a shoulder on the screw engageable with the control lever on rotation of the screw in one direction to hold the levers against relative movement `and disengageable from the control lever on Irotation in the opposite direction to permit relative movement between the levers.

2. For a burner fuel valve having a housing, a reciprocable valve actuating pin, and means biasing the pin outwardly of the housing in a valve opening direction, a control, comprising, means providing a fulcrum xed relative to the valve housing, an actuating lever pivoted on the fulcrum, a temperature responsive motor on the housing for pivoting the actuating lever in a valve closing direction, a control lever pivoted on said Afulcrum, an operating lever pivoted on said control lever and engageable with said pin, a toggle spring connected between said actuating lever and said operating lever biasing the operating lever against the control lever so that the three levers are movable in unison in a valve closing direction under urge of said motor, a stop on the control lever engageable with the housing to limit movement of the control lever in a valve closing direction beyond a predetermined low lire position, said motor being operable to pivot the -actuating lever laway from the control lever in a valve closing direction after engagement of said stop with said housing to snap said spring and operating lever overcenter away from the control lever to a valve closed position, and a selectively operable latch for locking the actuating lever to the control lever to prevent relative movement therebetween and thereby prevent the snap action valve closing movement of the operating lever comprising a screw threaded in one of the actuating lever and control lever land having a iirst abutment engageable with the other of the actuating lever and control lever on rotation of the said control lever and engagescrew in one direction thereby to draw and hold the two levers together.

3. A control for a burner fuel valve, comprising, a support mountable on a valve housing, a fulcrum on the support, `an actuating lever pivoted on the fulcrum, drive means on the support for pivoting the actuating lever in one direction -about the fulcrum, a control lever pivoted on the fulcrum, a valve operating lever pivoted on the control lever, a spring acting between the operating lever and the actuating lever biasing the operating lever against the control lever so that the three levers are movable in unison in said one direction under urge of said drive means, a stop on the control lever ttor limiting movement of the levers in unison in said one direction beyond a predetermined position, said drive means being operable to pivot the actuating lever away from the control lever beyond said predetermined position in said one direction to snap the operating lever and spring overcenter away from the control lever in said one direction, and a selectively operable lock for preventing the snap action of the operating lever overcenter relative to the control lever comprising a manually adjustable screw threaded in one of lthe actuating lever and operating lever and having a shoulder thereon engageable with the control lever on rotation of the screw thereby to prevent movement of said one lever relative to the control lever.

4. A selectively operable burner control system for optionally providing either a low re burner setting with a flow controlling valve in a partially open position or an oli setting with the valve in a closed position, comprising, a pivoted drive lever, a pivoted control lever alongside the drive lever, a valve operating lever pivoted on the control lever, spring means acting between the drive lever and the operating lever urging the operating lever against the control lever, movement of said drive lever acting through said spring to move said operating lever and control lever in unison to a valve partially open position, stop means limiting movement of the control lever whereby continued movement of the drive lever pivots the operating lever away from the control lever to a valve closed position, and manually accessible latch means for preventing pivoting of the operating lever on the control lever to the valve closed position comprising a Ilock member selectively movably mounted on one of the three levers and having a locking abutment thereon engageable with one other of the levers on selective movement of the lock member thereby to prevent relative movement between said one lever and said other lever.

Meacham Aug. 25, 1914 McCarty Oct. 4, 1955 

